It’s not really a surprise if you’ve seen the images before. This is the Nana that ends with high drama spelling out danger in episodes to come.

Spoilers beyond

Nana realises that if she’s ever going to get married she will need to have some money in the bank. She decides to put away the “marriage fund” money her mother deposited in the last (real) episode, and aims for a job with a publishing firm.
Shouji, meanwhile, decides to break off his friendship with Sachiko.

Shouji kicks himself into the abyss: the abyss of both parties knowing the wrongness of what they are doing. I can’t blame Sachiko for her tears because I’m not cynical enough to think she would be that manipulative, but I think that at least one of the two people in this situation should have had a stronger will power.
Junko may not have sided with Hachi when she was berating Shouji for stringing Sachiko along without realising it, but she most definitely would not approve of the course of action that he has decided to take.
“You knew Nana was exhausting when you decided to go out with her,” she tells him. He could at least have broken it off. That’s not to say I don’t understand that he was driven by impulse, and I’m certainly not saying that the situation is unrealistic: I’m just saying it’s wrong. I don’t really want to see Hachi break down because we’ve seen her paranoid about her relationship: imagine how awful it will be to watch her with something legitimate to worry about!

Shouji really is in a different world in the storyline, though, which makes the relationship dissolution so easy to understand. This delineation brings us to the world of Nana and Blast, the distraction that makes Hachi so happy. These scenes are an idyll that proves what Hachi says: “if she were a man, Nana would have been the love of my life. That’s how I thought back then.” Again the narration is at some far remove, and I’m really intrigued to think what has happened to change Hachi’s attitude.

Note that nothing I’ve said here is genuine criticism: just because I think something is wrong doesn’t mean I think it’s bad. Wrong is what makes stories go ’round, and Nana can only rock on from here.
(This is ignoring the people who decry any sort of emotional issues as “angst” and therefore “terrible to watch”. I’m not those people).